The Tragedy of Group Selectionism

Another excellent post.

If you don't mind me asking, roughly how long did it take to write, how long do you think it would have taken a year ago, and (assuming reading is already fast) what do you think are the most important factors that make writing speed go voom with frequent practice?

Obviously, selection on the level of the individual won't produce individual restraint in breeding. Individuals who reproduce unrestrainedly will, naturally, produce more offspring than individuals who restrain themselves.

Wrong. Sometimes quality, not quantity, matters. Which is why rabbits will abort and reabsorb fetuses when under stress, even though the reabsorption process has a significant chance of causing permanent infertility.

It's not about which organism produces the greatest number of offspring - although restricting fertility can sometimes lead to that - but the greatest number of surviving offspring. It's more complex than a madcap race to reproduce as rapidly and prolifically as possible.

Am I right in thinking that you've now brought the OB audience to where you need them in order to start trying to talk about AI (or "optimizing processes" or whatever terminology is sufficiently abstract to prevent linguistically inferred misunderstanding)?

Wrong. Sometimes quality, not quantity, matters.

Well, actually, it seems to be a case where a simple "ceteris paribus" would have taken care of that. If someone writes something that is easily fixed with a "ceteris paribus" or by some other simple means, I try to avoid saying "wrong".

My priors are not what they were a week ago. Thank you for the fascinating posts.

But the error isn't fixable simply by the addition of "all else being equal", because the important concepts that need to be addressed include the reality that some things are grossly unlikely to ever be equal.

There's a reason humans usually have only one child gestating at a time, even though it would be a simple matter biologically to have multiple fertilizations.

There's another reason the mouse gene that causes 90% of mouse sperm to carry a copy of itself in the heterozygous state and certain fetal/infant death in the homozygous doesn't cause mice to go extinct.

Discarding the concept of group selection is foolish. What's important is to recognize what factors are necessary and sufficient to permit group selection to occur.

Caledonian, delaying reproduction in order to maximize an individual organism's lifetime output is not the same as foregoing reproduction to benefit the chances of other organisms. The latter behavior is altruistic, the former behavior is not. Williams discusses this while showing that observed cases of apparent reproductive restraint match very finely the requirements of individual optimization.

Now I've said before that I can't include all the fillips and caveats in a series of blog posts. If you want to add a fillip in a comment, that's fine, but please don't assume that I'm ignorant.

I suggest reading the special issue of the Journal of Economic Behavior and Organization, January 2004, where the matter of multi-level evolution is dealt with at length, with some of the commentators evolutionary geneticists, mathematical ones at that, and at the highest level. The conditions for higher level selection are laid out there. Wynne-Edwards did not know these and was accurately put down by Williams in 1966. They are the Crow-Hamilton-Price equations. I suggest you read it, Eliezer, and, yes, I am the editor of the journal, the leading one in the world on evolutionary economics.

I thought I made it clear that I knew about the modern revival in multilevel selection. Was this not clear enough?

Group selectionism would later revive, somewhat, in drastically different form - mathematically speaking, there is neighborhood structure, which implies nonzero group selection pressure not necessarily capable of overcoming countervailing individual selection pressure, and if you don't take it into account your math will be wrong, full stop. And evolved enforcement mechanisms (not originally postulated) change the game entirely.

Barkley: got any explanations for why the supportable information in a genome should go as the inverse square of the mutation rate?

"Rationalisation of a predetermined bottom-line" is not always be a bad thing. It is common enough in Mathematics that you intuitively feel a result is right, and you work backwards from the result to see how you can prove it. The real mistake is if you do not take care in working it out backwards, and make wrong inferential steps in the chain. You may (legitimately) point out failures of this strategy, but there are also successes that you need to acknowledge.

Eliezer: It's still not at all unusual to see serious biologists advocating magical thinking. Evolutionary theory as conveyed in the undergraduate biology curriculum is extremely elementary, and it's easy to graduate without even mastering what is covered, not to mention without making single step inferences from it. Most biologists know no more about modern evolutionary than that plus the results of reading and for the most part believing either Gould or Dawkins. You can't assume that scientists are familiar with the sub-fields of their discipline, nor that they don't believe themselves to have some special expertise in those subfields due to their working in a related field. Of course, relative to the general population they do have special expertise in the related subfields, just not relative to specialists in those subfields working 50 or 100 years ago.

All: It seems to me that Caledonian is evolving into a troll. He's not there yet, but I suggest that a warning may be in order.

Venu: You definitely can do that in Mathematics, but that's because reasoning about Mathematics has some special properties that most reasoning about the real world does not.

1. Math is black and white If you find a proof for something, it's true. Until you do, you can't really call your hunch math. However, in the real world, it's very easy to find arguments for things that are false.
2. Math has monotonicity What this means is, that if you use Lemma A and Lemma B to prove Theorem Z, then whether or not Lemma C is true has nothing to do with whether your proof of Z still stands. The real world isn't like this, in that you can't arbitrarily pick a subset of the things you know to reason from. If A, B, C and Z were causally related events in the world, ignoring C would be cherry-picking your evidence.

The upshot is, if you try to backward chain from a conclusion in our non-monotone probabilistic world, you're quite likely to find a nice sounding but possibly flawed argument starting from cherry-picked premises. In fact, if your conclusion is wrong, you pretty much have to, unless your argument generator is so awesome that it fails to come up with arguments when you try to find one for a wrong conclusion. Sadly, we know from experience that the human argument generator isn't that awesome.

Eliezer,

Maybe I will get back to you on that point, and maybe I will not. I am about to leave town, and I spend 30 hours a week editing a journal, along with being a full professor of economics. This is why I turned down Robin's invitation to become a co-blogger here. Too damned busy. This is not meant to be a copout or an escape. I already spent a couple of hours I did not have last night digging through Gould again on your other posting.

I will note that the special issue I edited includes a wide variety of views and that there remain sharply contrasting opinions regarding the bottom line. Interestingly, the hardest line defenders of the Dawkins position (he was invited to participate, as were Tooby and Maynard Smith, although they declined), was a paper by GMU's Vernon Smith and Dan Houser, two economists. The political scientist, Axelrod, was also defending that view. The mathematical population geneticists were defending multi-level evolution, at least in principle under the right conditions.

For the record, I think you are a smart guy. If I have the time, I shall get into responding to your specific question. But I gotta go now.

No group selection? I believe the math in Eliezer's post is wrong. Here is how a hypothetical fox/rabbit population could evolve restrained breeding through group selection.

Picture a geographically isolated fox/rabbit population. At some level, this is guaranteed, simply because there's not an infinite amount of land on this planet to inhabit. Even if the entire planet was one continent with just rabbits and foxes, then that's the isolation geography. So at some point there won't be other foxes getting to eat the un-eated rabbits from the restrained fox population.

Start with a balance of rabbits and foxes. Perhaps this is because foxes are newly migrated to the area. Whatever. The foxes feast on the rabbits, because they are so easy to catch. The rabbit population drops to something that can metabolically support only 5% of the current fox population. As the foxes die out, any fox that has genes to restrain its breeding, is going to do better than foxes that don't, because it will spend less energy developing fox fetuses that won't survive anyway because there isn't enough food to go around. THIS IS THE KEY. If we assume all foxes are roughly equal at catching prey, then any fox family with constrained breeding will have more viable offspring because their mothers didn't die out trying to give birth to 6 foxes with food for only 2. Or the baby foxes, will go up stronger because food for 2 foxes is spread for just those 2, and not 6.

Now after this initial die off of foxes, the rabbit population will rebound. So won't the non-restrained breeders just take over again? No. As soon as the non-restrained breeders get large enough to diminish the rabbit population, the restrained breeders will have the same advantage they had the last time around. And even MORE of the unstrained breeders will die out removing even more of their genes from the gene pool.

Eventually, the non-restrained breeding genes become so rare it's as if they never existed. Only when they randomly pop up due to mutations would the cycle start again.

And here's where something almost magical happens. Every time those unrestrained breeders go crazy and eat all the rabbits, it does, to a certain extent, harm the survivability of the restrained breeders. Not as much as the unrestrained foxes, but enough. That means that any gene that will suppress the initial growth of an unrestrained fox population, will spread itself throughout the fox population. Perhaps a gene will arise that builds multiple chemical/hormonal systems in the fox to specifically restrain breeding, making it exceedingly difficult for any one mutation that un-restrains breeding to actually CAUSE unrestrained breeding.

Group selection. Tada.

Eliezer, just because the raw mechanics of evolution are very simple, doesn't mean bizarre and conceptually complicated things can't happen in the real world mechanics of evolution. Even if they SEEM counter-intuitive to the principles of evolution.

Wiseman, you are not describing group selection. You are still describing individual selection, because the causally effective advantage is to the individual. The benefit to the group is a side-effect. Here is your description of the advantage, which you call the key: "because it will spend less energy developing fox fetuses that won't survive anyway." That is an advantage to the individual foxes.

I also have doubts about the specifics of your scenario, but I won't get into that.

Constant, It's group selection because the individual is essentially making a sacrifice to reproduce less, to benefit the group. It happens blindly, through normal evolution of selecting the individual, but how else do you expect it to happen?

Eliezer -

Would "innovation" in genetic error correction, or changes to the proteins responsible for allowing greater or fewer mutations in DNA...

...would such "meta-changes" (changes to the mechanisms of DNA replication) be the basis for group selection?

If different groups had slightly different rules for their DNA replication, intuitively I could see that their competition would be best understood as group selection.

Consider two groups, both formed by mating of a single mother pregnant with a son, leading to two groups with slightly different rules for their DNA replication.

We might expect to see this if some population was regularly exposed to absolutely devastating conditions, where the often a population would have to recover from a single individual, a mother pregnant with a son.

If not this, how did "innovations" to DNA error correction and selection for the different rules about how many mutations to allow in DNA copying even form in the first place?

Constant, It's group selection because the individual is essentially making a sacrifice to reproduce less, to benefit the group. It happens blindly, through normal evolution of selecting the individual, but how else do you expect it to happen?

As I pointed out, the benefit to the group is a side-effect. In your scenario the fox survives because of a direct benefit to the fox. As for "how else" "I" expect it to happen, it's not about what I expect (since I am not advocating group selection), it's about what group selection is. As Wikipedia explains (and this is consistent with my outside knowledge, I quote it for convenience not authority): group selection is "the idea that alleles can become fixed or spread in a population because of the benefits they bestow on groups, regardless of the fitness of individuals within that group." That is not what is happening in your scenario, because, as you describe it, the individual fox that restrains its reproduction is more fit because it preserves energy. This is a benefit to the individual.

Wiseman, you need to put your scenario into mathematical terms, or write a simulation, or something. It's too easy to imagine some foxes and rabbits breeding and scurrying about, and convince yourself that something is possible. In any case the situation you described is not "group selection", but good old-fashioned gene-level selection. In this case it's selection for genes that lead to an optimal breeding rate.

(Oops, I didn't refresh for a while and I see you beat me to the critique, Constant.)

Constant,

Believe me, I fully see the obvious, but false, contradiction that you point out. Please understand I considered that when I first wrote my example.

It is ONLY a benefit to the individual because it's also a benefit to the group. Under ANY OTHER circumstances, a fox would do better for itself, and only itself, to reproduce more. But because the other foxes, the group, are around, the individual fox has to evolve for selection pressure not just from the non-fox enviroment, but the fox-group enviroment.

The benefit to the group is not a side effect, it's the cause. Without the group, the fox who reproduced more would not die out. The existence of the group is causing the selection pressure to select foxes who reproduce less, therefore benefitting the whole as much as the individual.

There is no group without the individual. Isolating the group, as if it has no relationship to the individual is purely illogical. To say that genes can benefit the group while at no point contributing to the survivability of just the individuals is a violation of the very basics of evolution. You don't need math to prove that.

Wiseman, I still disagree but am not going to pursue it.

This may be a stupid question but... what about kin selection? How did that develop? Wouldn't something like group selection have had to have happened at some point for kin selection to end up showing up in the first place?

ie, imagine a couple families/clans/whatever of some species. one happens to have a member that has "magic gene(s) of kin selection juju", and the other... doesn't.

Let's say eventually in the former, sometimes members having that gene get to breed just often enough so that the gene/complex/whatever starts spreading around through the family. Then, that would help promote the success of that family and thus that gene.

Or am I completely way way off here? And if so, how does kin selection develop in the first place then? Thanks.

Wiseman, you haven't shown that it really is beneficial to reproduce less in the scenario that you are describing. Yes, a smaller group will consume less food - but if there are six foxes, then the probability than at least one of them will survive can very well be higher than if there is only one. The group that reproduces less will still be outbred by the one that reproduces more, so the faster-breeding one could on average have more surviving members.

This might not be the case in situations where food is extremly scarce, but it should be so in situations where there is only enough food for, say, 80% of the population. Without running the numbers, it would intuitively feel that the fast-breeders have an advantage most of the time with the slow-breeders only having an advantage a small portion of the time - so while the exact gene frequencies will fluctuate, they won't give the slow-breeders a decisive advantage.

Kaj, fast breeding does not just incur a cost on the cubs, but on the mothers developing the cub fetuses. No matter the dearth of rabbits/food, as long as it's less than the amount needed to sustain the current fox population, the less energy and time spent by a fox mother developing unnecessary fetuses, the less likely she will die before child birth. You can't just calculate the raw probability of cubs surviving by saying "Each cub has X% chance of surviving, therefore the more cubs, the greater total chance that some will survive". A cub is taken care of primarily by it's mother, by nature of non-group selected genes. If each cub has roughly equal capability of aquiring food from the mother, that leaves the same amount of food for a larger number of cubs than the restrained breeding fox families. If 6 cubs have to share the amount of food that can only sustain 1 cub, it's likely no cubs will survive. Even if some cubs manage to horde more food than others, there still can only be so many surviving cubs based on the amount of food available, which will be the same amount as can survive from the restrained-breeder families. That means that the unrestrained breeder-mothers just spent much more energy and time producing the same amount of viable cub offspring as the restrained breeders, leading to a worse long term outlook for the survival of that unrestrained breeding family.

Psy-Kosh, kin selection means that you help those who are closely related to you, which helps spread your genes since those who are related to you are more likely to carry your genes. It's beneficial to breed, since (in sexual reproduction) your children share 50% of your genes. It's likewise beneficial to help your siblings, since they, too, share 50% of your genes. Hamilton's rule states that an allele for altruistic behavior will spread if the behavior it causes obeys the equation Br > C, where r is the relatedness between the actor and recipient, B is the benefit to the recipient and C is the cost to the actor, with B and C measured in surviving offspring. In other words, in order for altruism to spread, the behavior must spread your genes more than investing those resources to your own offspring would.

This is different from group selection, for you are only helping those who are very closely related to you (and therefore are likely to have the same allele), while in group selection you'd also be helping ones who didn't carry your genes and therefore harming yourself. Think of it this way - in order for an allele to spread, it must give its bearer a greater fitness than any alternative ones. An allele which helps everyone equally doesn't do that. Kin selection, on the other hand, does give a greater fitness to those who are more likely to carry the allele - in the form of help from their relatives.

Wiseman, it's true that the probability of survival for each cub depends on how much food it gets, which in turn depends on how many cubs the food has to be divided with. And yes, in extreme situations where the food is very scarce, having too many cubs means that they will likely all die - but I'm not convinced that the slow-breeder advantage during times of extreme scarcity will be enough to keep their numbers up during times of less scarcity, when they are being outbred. I'll try to quickly program a rough model for it to see what sort of numbers it produces (though I'm no evolutionary biologist).

Kaj: Ah, thanks. Then I guess I was a bit unclear as to what counted as group selection. ie, I thought a family would count as a "group" for these purposes.

I'll try to quickly program a rough model for it to see what sort of numbers it produces (though I'm no evolutionary biologist).

Never mind. I tried it, but realized that I had to resort too much to guesswork for it to be of any use. (Plus it's getting too late for me to really think about the model.)

Ok Kaj, I agree fast-breeders will at some points overwhelm slow/restrained breeders, at times where food is plentiful and greater than the amount needed to sustain the current fox population. But as long as that breeding goes unrestrained, the ecosystem enters a state which there exists less fox food than needed. As soon as that happens, restrained breeders have an inherint advantage because they waste less energy developing innevitably unviable fetuses. The important thing about this rule is it applies to any situation where they is less food than needed to sustain the current fox population. Even if it's only 99% enough food, the rule still applies. When I say 99% enough food to sustain the current population, I litterally mean that, and not states where there's less food so every fox has to go hungry sometimes. I mean metabolically, can the available food possibly sustain the current fox population? If not what's the advantage of giving birth to more cubs than could possibly survive anyway? How is that behavior going to lead to greater spreading of your genes? I don't see how it could.

I know it sounds like I'm repeating myself, but I just can't think of another way to state it. Perhaps it will come to me later.

Wiseman, you are not giving an example of group selection. You are imagining one single group (or two if we split the rabbits and foxes apart) over a long period of time. With group selection there are multiple groups, some of which die out on their own or get squashed/absorbed by other groups or the groups increase in size and split apart at different rates. For the rabbits/foxes example we could imagine multiple populations all separated and say that in all instances where breeding was not restrained, they overpopulated and died out, leaving only the ones that did restrain. However, all those populations would be vulnerable to the overbreeding mutation suddenly appearing, so it would not be a good explanation.

TGGP, your description of what group selection is is not in contradiction with mine. I merely described one isolated group, but the concept can apply to more than one of course. Imagine two groups of foxes and rabbits, one in which restraint is developed and selected for because of the greater health of their youth in times of famine, and one in which restraint is not in any gene, in which case the health of that population is generally lower than the restrained group, but still alive because it is not competing with any internal restrained-breeding individuals. This concept even works when the fox groups are isolated and the rabbit population is shared (however unlikely, that is possible.)

As for your last comment,

"However, all those populations would be vulnerable to the overbreeding mutation suddenly appearing, so it would not be a good explanation."

...I addressed the mechanics of why this wouldn't be a problem to group selection in my first post.

Barkley: The mathematical population geneticists were defending multi-level evolution, at least in principle under the right conditions.

How on earth could a mathematical population geneticist do anything else? In principle under the right conditions, you can create group selection in a laboratory and observe the results. Price's Equation in its various forms is a logical tautology. The question is whether the tautology has nontrivial empirical content: are group selection pressures tiny trivial things easily overwhelmed by individual selection pressures, or are they strong enough that evolutionary reasoning must routinely take them into account, or are they strong enough and persistent enough to create their own complex adaptations, over million-year timescales, involving significant organismal sacrifices of fitness; without any adapted enforcement mechanisms such as reciprocal altruism which make the behavior individually reproductively advantageous; without any adapted group boundaries such as cell walls; and without any enforcement of genetic identity such as in multicellular organisms?

It's the last part that is, to put it mildly, controversial; and it's what I've been referring to as "original" or "old-style" group-selectionist thinking.

It is a good rule of thumb that an amateur should never postulate group selection. Never ever never ever for never, as McCabe says. Somehow it's always an altruistic sacrifice to achieve some aesthetically beautiful consequence, rather than, say, cannibalism. And somehow they never do any math.

Professionals calculating whether spatial structure among self-replicating chemical hypercycles in tide pools could support adaptations leading up to the emergence of cell boundaries is a whole 'nother story.

Recovering: roughly how long did it take to write, how long do you think it would have taken a year ago

Probably at least eight hours. The publication time, just before midnight in California, should be a clue.

A year ago it would have taken months because it would have been part of a much huger document which included all the evolutionary posts into one giant blob, and I would have gone back and tweaked all the pieces instead of writing anything new.

The original plan was for this post on the tragedy of group selectionism to come directly after the post on Fake Justification. Then, when I tried to write the post, I found that I had to explain a whole lot of material on basic principles of reasoning about evolution, which detracted from the main point; so I split that off into "An Alien God". Then I noticed that "The Wonder of Evolution" could be taken out of "An Alien God" and make that post at least a little shorter. Then I figured I might as well do "Evolutions Are Stupid" and "Speed Limit and Complexity Bound" while I was on the topic, because I often have cause to refer to those equations. Then the "Gould" post because I often encounter people whom Gould has misled, and the complexity bound made a good illustrative case (though I'm presently in a state of mistrusting my math, if not Williams's heuristic argument and the observed number of human genes). Then I could finally get back to the original post on group selectionism...

Wiseman, you are not describing group selection. You are still describing individual selection, because the causally effective advantage is to the individual.

So repeat the logic, only substitute small, interrelated, relatively isolated groups of foxes for the individuals in the previous examples.

Populations can be the unit of selection just as individual organisms can.

Eliezer, I don't need to make assumptions about what you do and do not know when you make statements like "Obviously, selection on the level of the individual won't produce individual restraint in breeding." Either you've demonstrated your ignorance on the subject, or you've demonstrated that you can't convey your knowledge on the subject. From the perspective of your readers, the two possibilities are functionally equivalent.

Individual-level selection has produced LOTS and LOTS of individual restraint in breeding. This is not only obvious to biologists but to laypeople with everyday knowledge.

If you meant instead that organisms will not make sacrifies for general welfare unless the general welfare benefits the genes of the individual as well, you'd be right - but that is not what you said.

Dude, trying to gain an evolutionary advantage by "restraint in breeding" is like trying to get rich by overpaying your income tax. Hey, every extra dollar you give the IRS is one dollar removed from the national debt, which should improve the economy... and give you as an individual some utterly microscopic imperceptible benefit, w00t!

Dude, trying to gain an evolutionary advantage by "restraint in breeding" is like trying to get rich by overpaying your income tax.

No, it's more like putting your money into prudent long-term investments instead of buying lottery tickets. Trying to pump out as many offspring as possible is an extraordinarily bad strategy, which is why so few species ever attempt it. Even the ones that starve to death while guarding their tens of thousands of fertilized eggs don't try it.

Everything Wiseman is describing is happening at the level of the gene, not the population.

Imagine there is a gene for breeding rate - different variants of the gene give rise to different breeding rates (1, 2, .... offspring per year, let's say). A fox that has a high-rate allele of the gene will spend more energy on breeding than on caring for existing offspring, while the reverse is true with a fox that has a low-rate allele.

Given the natural fluctuations of food availability over the long term, there is going to be an optimal range of breeding rates. Genes that specify too high a rate will find themselves in bodies that spend too much time breeding to care for their offspring sufficiently, and such genes will not get passed on as frequently. Genes that specify too low a rate will be outcompeted. Caledonian is correct; it's like investing. But the investment pays off directly to the gene involved, so the fact that the vehicles and populations also benefit is an incidental.

To get group selection out of this scenario, you would have to have one fox group with a lower-than-optimal breeding rate, which let the rabbit population expand, which lessened the chance of a crash in food supply that would wipe out the population. Then that fox group would survive, and the neighboring groups would perish. But there is no way to enforce this pact of lower-than-optimal breeding rates in the first place.

You can alter the question slightly to permit a very limited form of group selection - you have to have completely isolated genomes, to start with, and a high level of mutative cost between the two groups. (I/e, mammalian versus octopus eyes - refinement guarantees the two groups can't crossover or mutate to adapt the other's characteristics.) If selective pressure favours one of the two characteristics, one group will be effectively "selected out."

The genetic variance doesn't even have to be defined - it could just be a selective tendency against. (I/e, groups for whom quality of children is more important than quantity may be more resistant to certain selective pressures, and vice versa - it isn't individual genes be selected upon in this case, it's the genome.)

So genomes, insofar as they may BE atomic, can be operated upon with selective pressure. Any atomic construct with reproductive capacity is subject to some form of evolution. It's simply much, much slower and rarer for larger constructs. (Because evolution on a smaller-construct form operates at such a high speed comparatively.)

Here are some Gene Expression posts on group selection. It is of course as Eliezer said, an empirical matter, but given the variation within populations compared to that between populations, it doesn't seem especially likely.

Group Selection (oh no not again!) Defining Group Selection: Price's Equation Group selection, the paramters Group Selection can work, just... (this features a model from Henry Harpending that would result in group selection, but the assumptions made may not be probable)

I've heard that E.O. Wilson is trying to wreck the consensus on group selection, but I don't know what he's found. Trivers has pointed out also that if group selectionism is important, it doesn't lead to aesthetically pleasing stuff either. It would likely cause bigotry between groups that care a lot for their in-group but not for their out-group.

Would the observed instances of Lamarkian inheritance change the debate re: group selection? http://www.newstarget.com/020068.html

To get group selection out of this scenario, you would have to have one fox group with a lower-than-optimal breeding rate, which let the rabbit population expand, which lessened the chance of a crash in food supply that would wipe out the population. Then that fox group would survive, and the neighboring groups would perish. But there is no way to enforce this pact of lower-than-optimal breeding rates in the first place.

Enforce? You don't need to enforce something that's build into organism's biology - and in the scenario you describe, their reduced rate would be the 'optimal' solution.

Even if a trait offers serious advantages in between-group competition, if it's a disadvantage in within-group competition, it will often dwindle and die out over time. What matters is whether the trait can make more copies of itself than will be eliminated; if it can't, there's no mechanism for it to persist, but if it can, one way or another, its frequency will increase. There has to be replication on the level of the group, not just on the level of the individual, for group-level benefits to cause traits to persist.

In an environment where new groups are frequently formed from randomly-selected subsets of previous groups, and groups compete with each other, the founder effect can amplify the frequency of traits that benefit the group but are disadvantageous for the individuals carrying them. Now groups are acting as a unit of replication, and so selection forces can maintain traits on this level.

This is why mice don't go extinct even though they're parasitized by the replicator gene. Sure, the gene rapidly dominates any group it's introduced to, and prevents successful reproduction within that group, but there are enough obstacles to divide the total mouse population into smaller groups in the short term. Inside any one group, not having the gene loses out to having it every time. But the constant establishment of new groups, and the temporary limits to gene spread between groups, together make it possible for the gene-absense to persist. If you removed the restrictions on gene flow the parasite gene would spread throughout the entire mouse population and they'd all die out. If there aren't enough distinct groups, group-level selection doesn't 'work' - just as individual-level selection doesn't 'work' when there aren't enough individuals.

I'm back.

Eliezer,

I agree that ultimately the empirical issue will be more important than this model versus that model. I am not going to get into the debate about the specific math of your model as others have already done so. If you really think you have a strong and new result, submit it to my journal. The referees will be some of the top mathematical population geneticists in the world.

McCabe was the third coauthor on the piece with Smith and Houser of GMU in the Jan. 2004 JEBO special issue that took the hardest pro-Dawkins line. So, when he says "never never never..." this factoid should be kept in mind.

Also, if you do submit the paper, change the title. Indeed, while "Tragedyy of Group Selection" may get the adrenaline flowing for some readers, it is pretty absurd. Tragedy? Who died or was killed or even just had their marriage break up? (maybe a couple arguing about group selection?). Hitler's racist eugenics was tied to millions being killed in the Holocaust. That was tragedy. Stalin's support of the goofy Lamarkism of Lysenko was tied with millions dying in Soviet famines and many better scientists being thrown in jail for disputing Lysenko. This was a tragedy. Get real, please.

Oh yes. While you suggest that the hypercycle is a "whole 'nother story," I would say not really. There are links, even if the precise equations are somewhat different.

TGGP,

Congrats on the reasonably informative links.

Caledonian,

Once you are dealing with hominids, which may be the most important example, indeed "enforcement" may well be important. There is a growing lit on how reciprocal altruism ultimately depends on punishment of free riders, that is, enforcement.

Rosser: I am not going to get into the debate about the specific math of your model as others have already done so.

There's only one equation in this post and it's a standard one. Were you referring to the Speed Limit post? I already put all original math in that post into abeyance pending further investigation.

I'm reasonably certain the McCabe I was quoting isn't your McCabe.

I suppose I have a unique professional perspective on how tragic the class of warped thinking revealed in old-style group selectionism is likely to be. ("You can get all these wonderfully aesthetic results just by optimizing for criterion X - oops the real result is cannibalism.") Future posts should make this clear.

"Once you are dealing with hominids, which may be the most important example, indeed "enforcement" may well be important. There is a growing lit on how reciprocal altruism ultimately depends on punishment of free riders, that is, enforcement."

That sounds to me like an example of an "Evolution Fairy".

Eliezer,

So, who is your McCabe?

Wiseman,

Wise crack.

Once you are dealing with hominids, which may be the most important example, indeed "enforcement" may well be important. There is a growing lit on how reciprocal altruism ultimately depends on punishment of free riders, that is, enforcement.

Really? I'd thought that was generally understood - that was the whole point of Tit for Tat, after all, that it could both reward cooperative behavior and punish defection. One without the other is useless: kindness without cruelty is weak, cruelty without kindness self-destructs.

But the point I'm trying to get across isn't about altruism, but group-friendly behavior in general. Altruism is an important subcategory, certainly, but there's a wider case to be made.

And Eliezer is STILL wrong in his earlier quoted statement. Why am I not surprised?

This might be a bit off-topic but I have a post that discusses misunderstanding Darwinism and how irrelevant what pleases us is to the evolutionary process, the distinction between natural and artificial selection and the issue of social interaction. It's mostly about that weird kid who shot up his school in Finland though.

Glad you liked the links Barkley. I wish I could have found the link on Trivers I was half-recalling though. Here is a link on E. O. Wilson and group selection.

Caledonian,

Your distinction between altruism and the more general "group-friendly" is useful and relevant.

TGGP,

Regarding artificial selection it is worth remembering that this was one of the major examples that Darwin himself emphasized in Origin of the Species, the efficacy and effect of efforts at artificial breeding and selection by humans of both plants and animals.

In the brief period of time since I last commented two new good posts on group selection, E.O. Wilson and how it does not gel with our aesthetic/moral preferences have appeared.

'Would "innovation" in genetic error correction, or changes to the proteins responsible for allowing greater or fewer mutations in DNA...'

'...would such "meta-changes" (changes to the mechanisms of DNA replication) be the basis for group selection?'

If they can't interbreed, then you get selection like that between two different clones of bacteria. Either the better species survives, or they both survive in their own ecological niches.

If they can interbreed then you might get evolution by group selection but it isn't the way to bet. You'd want a specific case for a particular gene.

'If not this, how did "innovations" to DNA error correction and selection for the different rules about how many mutations to allow in DNA copying even form in the first place?'

Given alternative genes that result in alternative behaviors (either from different enzymes or different regulation of those enzymes or something else) -- the one that works better results in its individuals outcompeting other individuals. That's what natural selection involves. The way you know it's fitter is that the gene frequency increases. We hope that on average things that increase gene frequency also improve survival of the individuals that carry them, and improve survival of the population. But there are examples otherwise.

Sometimes genes can increase because of selection among groups. This can happen but it's a complication that tends not to happen.

How does a mutation in a gene for mutation rate get changed in a population? When it starts out it's outnumbered a hundred million to one. The first favorable mutation that happens will almost certainly be among one of those hundred million and not in the single mutant.

And further, given mutations that are all about as good, the first one to get established gets the lion's share of the results. However, in a large population the mutation that makes a better mutation rate will happen occasionally in individuals that have a favorable mutation, and will spread with them. In the absence of selection against it, it will reach a fluctuating equilibrium for that reason. And this subpopulation will mutate at a better rate, and the result is that it will increase some with each population changeover. With each changeover the better mutation-rate mutants will tend to increase at the expense of the worse mutation-rate variants. Slow but reasonably sure, given a large population.

It's possible for genes to evolve that regulate things like mutation rate. They might increase the rate or decrease it according to whatever cues seem to work well on average. Selection can work to let populations evolve faster, and it's selection on indvidual genes (or combinations of genes) that does it.

It's possible to get genes that improve the survival of groups. But unless they spread they have limited chance to improve group survival.

TGGP, Steve Sailer's post seems to me to confuse executing adaptations versus maximizing fitness: "The good news is that conquering land really doesn't pay these days, so peace has become, from a group-selectionist point of view, more rational than in the past." So what? Modern humans will go on executing the conquest adaptation.

I wish I could have found the link on Trivers I was half-recalling though.

Could it be something like this exchange between Trivers and the authors of "Unto Others". Some of the comments from Trivers are priceless.

Caledonian is right, it's not a "fillip" to point out that reproductive restraint can evolve by individual selection in the sense of K-selection, not in the sense of altruism. To be fair, several recent articles in favor of group selection also talk about "reproductive restraint" and mean altruism, but that doesn't IMO excuse it. Any adaptation leading to late reproduction and less offspring in, say, elephants, must have looked like "reproductive restraint" at some point (although not necessarily at the level of numbers of grandkids, which is the true measure of fitness).

Wiseman's misunderstanding of group selection demonstrates why this would have been an important distinction to make.

Caledonian: ...mice don't go extinct even though they're parasitized by the replicator gene. Sure, the gene rapidly dominates any group it's introduced to, and prevents successful reproduction within that group, but there are enough obstacles to divide the total mouse population into smaller groups in the short term.

I think you are wrong about the mouse t gene, though. Individual selection is working against gene selection within each mouse population. I haven't seen accounts that group selection is necessary here, or do you have a ref?

Sadly, I do not have a reference currently, or I would have put the scientific name of the gene variant in question.

What I recall - which may or may not be accurate - is that the gene has a minor negative effect on the overall reproduction of heterozygous males, but not enough to matter on the short scale during which it spreads through the population.

Windy, group selection has been hypothesized to be necessary or sufficient in this case almost from the time the gene was first observed.

Presumably other genes could counteract its effects for an alternative method to prevent extinction. Such genes would be weakly selected while the t allele was rare and very strongly selected when it was common. Strong founder effect.

theoretical study:
https://lirias.kuleuven.be/handle/123456789/41135

I too remember a description of a small reduction in survival of heterozygous individuals, which doesn't nearly balance the increase in survival of the gene. And I too don't have a link handy for that.

T gene is one scientific name of the variant - or rather "t haplotype". Geneticists are not as anal about names as taxonomists...

Wiseman's misunderstanding of group selection demonstrates why this would have been an important distinction to make.

Windy, the point you referred to from Caledonian is not different than my own, so clearly it is you who is misunderstanding something here.

I "get" what group selection is, as you know, at the high level it's not a difficult concept. But my point in an earlier argument is that the idea of group selection can logically only mean one thing, and it is not the idea that somehow the group can flourish while the individuals are slowly dying out, due to actual decreased fitness, that is a logical paradox that cannot be resolved. There seems to be exceptionally high expectations from group selection in this sense. Unrealistic expectations.

If you take away that paradoxical definition of group selection, and consider the only logical alternative, 'group selection' now becomes how can the group of individuals evolve in a way in which changes how the individual survives to benefit not just itself but also the group, but not the degree to which the individual survives. In this sense of group selection, evolution at the 'gene level' is not forbidden from partaking in group selection. Remember, if the degree to which the individual was able to survive decreased, if it was actual decreased fitness, we arrive back at the paradox where somehow the group is flourishing while all the individuals of that group are dead.

Windy, the point you referred to from Caledonian is not different than my own, so clearly it is you who is misunderstanding something here.

Your scenario is plausible, it's just not group selection. It's K selection. Just because "group" is mentioned in the scenario doesn't make it group selection.

Your definition also makes every adaptation that rescues a group from extinction an example of group selection. What's special about reproductive restraint? Antibiotic resistance is group selection, since otherwise that population would go extinct. Industrial melanism is group selection, since otherwise that population would(might?) go extinct.

Remember, if the degree to which the individual was able to survive decreased, if it was actual decreased fitness, we arrive back at the paradox where somehow the group is flourishing while all the individuals of that group are dead.

"Actual decreased fitness" does not mean "all will die". If it is logically impossible for "actual decreased fitness" to evolve, how do you explain worker ants? (ignore for the moment whether it's kin or group selection or what, just consider what the fitness of the workers is.)

Oh, and here's some data on fox reproduction. What would you expect X and Y to be before checking the actual data?

-Of the X to X+1 cubs born to an average fox litter, an average of Y to Y+1 survive the first year.

Windy, according to my logic, yes, to a certain degree all adaptations contribute to some sort of group survival, thus negating the importance of drawing the distinction between group and individual/K selection as some sort of fundamental difference in the mechanics of evolution.

That doesn't mean I'm saying 'group selection' is not a valid area of study, it still needs to be resolved how some adaptations which seem detrimental to the individual end up being good for the individual by proxy of the being good for the group. This is not so much a redefinition of 'group selection' as it is lowering the expectations of what group selection can be expected to accomplish, namely not being able to resolve some impossible logical paradox.

"Actual decreased fitness" does not mean "all will die". If it is logically impossible for "actual decreased fitness" to evolve, how do you explain worker ants? (ignore for the moment whether it's kin or group selection or what, just consider what the fitness of the workers is.)

If you are talking about genetic fitness, the pure ability to continue the genetic line, yes it does mean eventually all will die. I am not giving any importance to an arbitrary definition of 'health', which is not always important to genetic survival. If the organism reproduces successfully from generation to generation, then it is fit, period. The more it reproduces successfully, the more fit. Existence of the genome in an active form is the only important factor.

So to reinforce the impossibility of the paradox, if the group is able to continue its existence generation after generation via the survival of the individuals within that group, then the individuals must themselves be 'fit', mustn't they? No matter the bizzarity of how they are able to reproduce, they do, which is why the group survives.

Worker ants are explained because through the breeding structure of an ant colony, the worker ants behavior ensures a genome very similar to it's own will continue to exist. It effectively is protecting its own genome even if won't actually get to reproduce with its exact genome.

Hi Eliezar

Two questions
1) Which equation in the D.S. Wilson paper are referring to with your C/B < Fst equation formula relates to the paper, this look more like Hmailton's equation which Wilson is, indirectly, criticizing and trying to show that this (kin selection) is a sub-set of multi-level selection. Where are the two levels of selection in this equation which is the key basis for modern group selection formulations?

2) Why not use a criticism of group selection based on claims that are currently being made rather than a discredited scenario (Wynn-Edwards argument here - which he thinks can now be rehabilitated but this is a minority position) such as Wilson and Hölldobler's work on insects? The scenario you used looks is misleading as most modern group (multi-level) selectionists would not refer to such a scenario and explanation for support.

Eliezer's report of Wade's study is not completely accurate. From the link, emphasis mine:

...some of the B populations [the ones selected for low population] enjoy a higher cannibalism rate while other B populations have a longer mean developmental time or a lower average fecundity relative to the controls.... Thus, the decline in mean population size in the B treatment... is the result of both group selection and individual selection within populations favoring characters responsible for low population size....

In summary, these results indicate (i) that group selection in the opposite direction to individual selection can produce significant genetic change, (ii) that group selection in the same direction as individual selection can produce results very different from individual selection acting alone, and (iii) that a process of random extinctions with recolonization can establish conditions favorable to the operation of group selection.

[...] and if you don't take it into account your math will be wrong, full stop.

And... I just now realized that "full stop" is functionally equivalent to "period."

[...] and if you don't take it into account your math will be wrong, period.

"Full stop" says the same thing but avoids the negative reaction that "period" brings. Clever. It was bugging me for the last few times I saw it but I didn't figure out why until this article.

EDIT: Haha, this got downvoted? I guess I didn't see that coming. Ah well. It'll probably go back up. And then go back down.

This is just a nitpick: according to The Other Wiki democratic constitutions are older than English kings, the most egregious example being The Solonian Constitution after reform by Cleisthenes, which codified Athenian "democracy". Yes, I know, semantics.

Yudkowsky, is this where your Babyeating aliens from Three Worlds Collide come from?

See my post about an experimental validation of group selection among nightshades.

Suppose an organism of an A genotype emits pheromons depressing development of female reproductive organs in receptive organisms of same population (with an aa genotype), and so gains resources for its own reproduction during a given season, and then during the next season it doesn't emit the pheromon (through some environmental regulation/...) and the homozygotes of the population get a chance to reproduce... Does this count as group selection? It would be still the same species, since the A can receive sperm from any genotype, and use of resources can be regulated. (I'm just trying to apply 'group selection' to anything without a nervous system, and having trouble. It seems to me lately that your 'evolution' is a rather selective concept.)

Reminds me of one of the early AI research projects using some variety of optimization algorithm to try to "learn" the ability to solve a wide variety of problems in a single program.  Genetic algorithm I think, random mutation and cross-pollination of the programs between the best performers, that kind of thing.

After a while, they noticed that one of the lines that had developed, while not the best at any of the test problems, was second-best at all of them.

Yet when they tried to make it the base of all their next generation...  it didn't work...

Cue a massive analysis effort to rip it apart at the machine-code level and figure out what the heck was going on.  Eventually they found that it had stumbled upon a security flaw in their running environment and learned to steal answers from the other programs running on the system.

Evolution doesn't care if it's cheating, only if it works.